Control circuit for driving stapling mechanism

ABSTRACT

A control circuit for driving a staple forming and punch apparatus incorporating an inductance coil, a first circuit coupled to the inductance coil including an SCR device and a second circuit including a second SCR device and DIAC device. A control energizes the DIAC device to fire at predetermined intervals so that said second SCR device may be turned on and the first SCR device turned off.

United States Patent Kukucka et al. [451 Mar. 28, 1972 s41 CONTROL CIRCUIT FOR DRIVING 3,295,421 1/1967 McCormick ..3o7/2s2 M STAPLING MECHANISM 3,334,243 8/1967 Cooper ..307/293 [72] inventors: William P. Kukucka, Henrietta; James E. Primary Examiner john Zazworsky Summers Falrpon both of Attorney-James J. Ralabate, Norman E. Schrader and Melvin [73] Assignee: Xerox Corporation, Stamford, Conn. Klein [2]] Appl' 70832 A control circuit for driving a staple forming and punch apparatus incorporating an inductance coil, a first circuit cou- [52] -S-Cl- ..307/252 M, 307/252 K, 315/340 pied to the inductance coil including an SCR device and a 51 1111.0; ..l-l03k 17/00 second circuit including a Second SCR device and DIAC [58] Field of Search ..307/252 J, 252 K, 252 M, 252 W; vic A ntrol energizes he DIAC device to fire at 315/340 predetennined intervals so that said second SCR device may be turned on and the first SCR device turned off.

[56] References Cited 5 Claims, 3 Drawing Figures UNITED STATES PATENTS we 7 v r 1 ClR/ CR3 CR5 N 1 1 2 CR2 R3 SOLZ K3 s1 CR6 l|5vAC I 2 l 02 TI I CR8 02 01 g L c4 17 R9 R8 PATENTEDMAR28 1912 3. 652,875

sum 1 [IF 3 INVENTORS. WILLIAM P. KUKUCKA JAMES E. SUMMERS BY WW ATTORNEY PATENTEB MR 2 8 I972 SHEET 2 [IF 3 FIG. 2

CONTROL CIRCUIT FOR DRIVING STAPLING MECHANISM This invention relates to apparatus for fastening sheet material into booklets, and in particular to a control circuit for driving a stapling mechanism.

As is well known in the art of bookmaking, it is generally necessary to first print or copy sheets and then gather groups of different sheets in a definite order referred to as collating. The operation of printing and then assembling sheets into booklets usually requires several steps, the last of which is taking one sheet from each of the stacks and putting these sheets together in the order desired.

Normally the assembling of the sheets and then stapling the sheets into booklets is slow and cumbersome. Also, present devices for fastening the sheets into booklet form have the disadvantage of being prolix and costly and have not been entirely satisfactory.

The present invention enables automatic stapling of sheet material into booklets. To accomplish this, a stapling mechanism incorporating a control circuit is used to energize a solenoid to actuate a punch and staple forming members for a predetermined interval during a drive stroke. ln this manner, the sheet material is properly fastened and the stapling mechanism returned to a rest position to commence another cycle.

It is therefore an object of the present invention to improve the printing of booklets.

It is another object of the present invention to improve the stapling of sheet material.

lt is another object of the present invention to enable producing sets of collated copies from precollated document material to be reproduced.

It is another object of the present invention to provide a control circuit for forming a staple and then fastening the formed staple into a work piece during a single power stroke.

These objects as well as others will become more apparent upon considering the following description which is to be read in conjunction with the accompanying drawings in which:

FIG. I is a perspective view of a copying machine incorporating a finishing apparatus according to the present invention;

FIG. 2 is a side sectional view of the finishing apparatus;

FIG. 3 a diagrammatic showing of the staple drive circuit.

GENERAL For a general understanding of reproduction apparatus with which the present invention may be incorporated, reference is made to H6. 1 wherein various components of a typical electrostatic printer system are illustrated. The printer system is of the xerographic type and is generally designated with the reference numeral 10. As in all xerographic systems, a light image of an original to be reproduced is projected onto the sensitized surface of a xerographic plate to form an electrostatic latent image. Thereafter, the latent image is developed with toner material to form a xerographic powder image corresponding to the latent image on the plate surface. The powder image is then electrostatically transferred to a record material such as a sheet or web of paper or the like to which it may be fused by a fusing device whereby the powder image is caused permanently to adhere to the surface of the record material.

The xerographic processor indicated by the reference numeral 11 is arranged as a self-contained unit having all of its processing stations located in a unitary enclosure or cabinet. The printer system includes an exposure station at which a light radiation pattern of a document to be reproduced is positioned on a glass platen 12 for projection onto a photoconductive surface in the form of a xerographic belt 13. The document is transported by a recirculating document feed apparatus 15 from the bottom of a stack 17 on a supply tray 19 to the platen for exposure and then returned to the top of the supply tray on completion of the exposure until the entire stack has been copied at which time the cycle may be repeated as described in copending application Ser. No. 781,287, filed on Dec. 4, 1968, entitled Document Feed Apparatus and commonly assigned with the present invention.

Imaging light rays from the document as flash illuminated by lamps 18 are projected by a first mirror 20 and a projection lens 21 and another mirror 23 onto the belt 13 at the focal plane for the lens 21 at a position indicated by the dotted line 25.

As an interface structure and for unobstructive optical projections, the side of the cabinet is formed with an enlarged rectangular opening to permit the projection of image light rays from the lens 21 to the mirror 23. Similarly, the cabinet supporting the document plane is formed with a corresponding rectangular opening that mates with the opening in the printer cabinet when the two cabinets are operatively joined together for copy/duplicating purposes. Suitable light-type gaskets may be utilized adjacent the exterior of each opening in the cabinets in order to minimize the leakage of unwanted extraneous light.

The xerographic belt 13 is mounted for movement around three parallel arranged rollers 27 suitably mounted in the frame of processor 1 l. The belt may be. continuously driven by a suitable motor (not shown) and at an appropriate speed corresponding to the discharge responsive the photoconductive material that comprises the belt and the intensity of the imaging light rays from the document. The exposure of the belt to the imaging light rays from the document discharges the photoconductive layer in the area struck by light whereby there remains on the belt an electrostatic latent imaging of figuration corresponding to'the light image projected from the document. As the belt continues its movement, the electrostatic latent image passes a developing station at which there is positioned a developer apparatus 29 for developing the electrostatic latent image. After development, the powdered image is moved to an'image transfer station whereat record material or sheet of paper just previously separated from a stack of sheets 30 is held against the surface of the belt to receive the developed powder image therefrom. The sheet is moved in synchronism with the movement of the belt during transfer of the developed image. After transfer, the sheet of paper is conveyed to a fusing station where a fuser device 31 is positioned to receive the sheet of paper for fusing the powder thereon. After fusing of the powder image, the sheet is conveyed through an opening in the cabinet to a finishing apparatus 32 for stapling or side stacking in a manner as will be described more fully hereinafter. The sheets are separated from the stack and fed from the top of the stack by means of a separator roll device 33 and timed sequence of the movement of the developed latent images on the belt 13.

Further details of the processing devices and stations in the printer system are not necessary to understand the principals of the present invention. However, a detailed description of these processing stations and components along with the other structures of the machine printer are disclosed and copending application Ser. Nos. 731,934, filed May 24, 1968, and 756,598, filed Aug. 30, 1968, which are commonly assigned with the present invention.

It will be appreciated that the printer system may be operated in conjunction with a roll converter unit indicated by the reference numeral 35. The roll converter unit 35 is adapted to convert a relatively large roll of paper 36 into various sizes of sheets of paper by means of a cutter device 37 and a suitable control system (not shown) arranged to control cutting and feeding of the individual sheets into operative cooperation with the separator roller 26. it will be appreciated that operative cooperation is assured between the various units operating with the printer system by the physical association of the cabinets for the units and the matching openings which enable full cooperation of the imaging light rays and sheet transport path between the units. In this regard, locking clamps may be provided on all the units for preventing the inadvertent movement of such units during use and interlocks which is an alignment device may be utilized on each unit for ensuring upper alignment and to terminate or suspend operation in the event mis-alignment or separation of the units occur. For facility and needs of operation, each of the units provided with caster wheels and locking brakes thereby aiding in the movement of the units into and out of cooperative engagement.

FINISHING APPARATUS The finishing apparatus 32 comprises a frame 50 having a main body housing 51 and cover 52 which is connected to the frame by rods 54 and 55 against the action of spring sets 57 and 59 encircling the rods to enable a pop open position of the cover as well as a fully raised position to permit access into housing 51. Housing 51 has hook members 61 extending from the lower portion to secure the frame to the processor ll as previously mentioned.

Finishing apparatus 32 includes an input receiving tray assembly 70, a stapler group 72, a stapler head assembly 74, a side stacking assembly 76 and an output receiving tray assembly 78. Input receiving tray assembly 70 comprises an adjustable input receiving tray 105 which serves to guide the sheet material along a path from the processor into the finishing apparatus. The tray is adjustable for varying paper width which may accept, as for example, 8% X 11 paper up to 9 X 14 paper.

STAPLE GROUP ASSEMBLY The staple group assembly 72 comprises a registration gate 207 which stops the forward motion of the sheet material, a paddle wheel 209 which moves the sheet to the forward lefthand corner of the input receiving tray for stapling by stapling head assembly 74 which drives staples into the sheet material positioned on the receiving tray to produce finished booklets.

Gate 207 stops the forward motion of the sheet material and is received in a slot 235 formed in the input receiving tray. Gate 207 is maintained in a rest position in slot 235 by the action of a spring 237 and can be actuated to a raised position above the sheet path by the energization of a solenoid SOL-1 as will be described hereinafter. The stapling head assembly 74 places staples into the sheets collected on the input receiving tray having been positioned in comer registration against paper guide 107 and gate 207. For this purpose, staples are in the form of a roll and are held together by a suitable coating which roll is commercially available under the trade name Swingline, manufactured by Swingline, Inc., Long Island City, N.Y. Typically, the staple length is about 1 inch such that a crown of about 9% inch can be formed from the staple when inserted into the sheets forming booklets. The staple length, of course, can be varied depending upon the number of pages or sheets which are to be stapled to form a booklet. Staples are fed from the roll 241 by the action of the driving elements of the stapling head assembly 74.

STAPLE CONTROL CIRCUIT In order to achieve a reliable operation, a control circuit is associated with the stapling head assembly to provide a predetermined pulse of sufficient duration to maintain the driving stroke and staple forming operation of the stapling head assembly. As shown in F IO. 16, the staple driving circuit comprises a full wave bridge rectifier CR1 which provides a signal input to SCR Q2 and also an input to the coil of solenoid SOL-2 through a diode CR5. It will be noted that one side of the coil of solenoid SOL-2 is connected to another SCR Q1. The other side of the coil is connected to a terminal of the full wave bridge rectifier CR1. The same side of the coil which is connected to CR1 is also connected to a capacitor C1 which is coupled through a diode CR4. A transformer T1 is coupled to capacitor C1 through diodes CR2 and CR3. Transformer Tl serves to charge up the capacitor C1 continuously. At the same time, a charging current is also provided by the bridge CR1 through the diode CR5 and resistor R2. It will be noted that capacitor C2 also couples the SCRfs Q1 and Q2.

In operation, a reed switch S1 which is coupled to the coil of a relay K3 upon actuation of the relay turns on SCR 01. At the same time, the relay serves to shutoff SCR 02. It will be noted that O2 is coupled to the bridge CR1 and will be shut off with each half cycle. It will be further noted that SCR 01 which receives its power input from the transformer T1 in the fonn of a DC signal after passing through diodes CR2 and CR3 will allow a power input supplied continuously to SOL-2 unless O1 is otherwise turned off. ln order to maintain an input pulse of a predetermined duration sufficient to accomplish the stapling operation, the coil of solenoid SOL-2 receives its input signal from SCR Q1 which will remain on until shut off by O2. in order to shut off Q1, reed relay switch S1 is de-activated by de-energizing relay K3 thereby moving the reed switch from a terminal 2 to a terminal 1. At this time, a power input from the bridge CR1 is then coupled with diac CR8 which will not turn on Q2 until a sufficient voltage has been built up on capacitor C3 to turn off SCR Q1. A capacitor C4 and a resistor R10 ensure that Q1 will not turn on immediately after being turned off. The resistance of a resistor R3 is sufficient to enable the voltage build up on capacitor C2 to be completed before diac CR8 is ready to fire. By this ar rangement, when 02 turns on, Q1 will be turned off and coil of the solenoid SOL-2 will be de-energized ensuring that the stapling head assembly is returned to its rest position ready to commence another cycle. To discharge the transient from the inductance of the solenoid coil when SCR O1 is turned off, a resistor R4 and a diode CR6 are provided.

What is claimed is: 1. A control circuit for driving a stapling mechanism comprising an inductance coil, first circuit means coupled to said inductance coil to supply discrete electrical pulses to said inductance coil, said first circuit means including first semiconductor switching means for controlling the input pulses to said coil, second circuit means including second semiconductor switching means for shutting off said first semiconductor switching means at predetermined intervals, said second circuit means including third semiconductor switching means, control means for supplying signals to said second circuit means to energize said third semiconductor switching means to fire at predetermined intervals so that said second semiconductor switching means may be turned on and said first semiconductor switching means turned off,

said first circuit means includes a transformer, rectifier means, and a capacitance between said inductance coil and said first semiconductor switching means to establish a high voltage input into said inductance coil.

2. A control circuit according to claim 1 wherein said second circuit means includes rectifier means and a capacitance for establishing pulsating DC reference signals to said third semiconductor switching means.

3. A control circuit according to claim 1 wherein said first semiconductor switching means and said second semiconductor switching means are coupled by a capacitance operative to charge up to a voltage in time period which is less than the time required for firing said third semiconductor switching means.

4. A control circuit according to claim 1 including a resistance and a capacitance across said first semiconductor switching means for prohibiting said first semiconductor means from being turned on immediately after being turned off.

5. A control circuit according to claim 1 wherein said first circuit means includes a resistance coupled by a diode to said first semiconductor switching means to prevent current surge to said first semiconductor switching means. 

1. A control circuit for driving a stapling mechanism comprising an inductance coil, first circuit means coupled to said inductance coil to supply discrete electrical pulses to said inductance coil, said first circuit means including first semiconductor switching means for controlling the input pulses to said coil, second circuit means including second semiconductor switching means for shutting off said first semiconductor switching means at predetermined intervals, said second circuit means including third semiconductor switching means, control means for supplying signals to said second circuit means to energize said third semiconductor switching means to fire at predetermined intervals so that said second semiconductor switching means may be turned on and said first semiconductor switching means turned off, said first circuit means includes a transformer, rectifier means, and a capacitance between said inductance coil and said first semiconductor switching means to establish a high Voltage input into said inductance coil.
 2. A control circuit according to claim 1 wherein said second circuit means includes rectifier means and a capacitance for establishing pulsating DC reference signals to said third semiconductor switching means.
 3. A control circuit according to claim 1 wherein said first semiconductor switching means and said second semiconductor switching means are coupled by a capacitance operative to charge up to a voltage in time period which is less than the time required for firing said third semiconductor switching means.
 4. A control circuit according to claim 1 including a resistance and a capacitance across said first semiconductor switching means for prohibiting said first semiconductor means from being turned on immediately after being turned off.
 5. A control circuit according to claim 1 wherein said first circuit means includes a resistance coupled by a diode to said first semiconductor switching means to prevent current surge to said first semiconductor switching means. 